Wine testing is used at wine production facilities, and also at higher-end restaurants and by individual wine enthusiasts. However, conventional wine testing methods generally require direct access to the wine and cannot be performed on wine inside closed bottles. Thus, for wine that has already been bottled, such conventional wine testing is necessarily invasive.
One prior art method for non-invasive testing of wine in bottles utilizes nuclear magnetic resonance (NMR) spectroscopy to at least partly characterize the chemical composition of the wine. The NMR instrument is very expensive and large. Therefore, the NMR approach is not well-suited for small-scale wine testing at decentralized locations by restaurants, wine shops, or consumers.
Another prior art method uses a radio-frequency coil to measure dielectric properties of wine in bottles. The coil encircles the bottle and cooperates with electronics equipment to detect changes in the inherent resonance frequency of the wine at frequencies below 30 megahertz (MHz). This method requires significant electronics equipment. The interface with the bottle, e.g., the radio-frequency coil, must be large in order to encircle the bottle. In addition, wine bottle labels commonly have metallic print that interferes with the measurements and is likely to cause the measurement to fail.